| Objective:In this study,inorganic arsenic was used as an exposure factor to investigate the effects of inorganic arsenic exposure on DC antigen-presenting function and the possible regulation of p62 dependent Nrf2 activation.The possible mechanism,in turn,and provide clues and theoretical basis for the long-term carcinogenesis of arsenic poisoning.Methods:1.Mouse BMDCs induced culture and preparation of mouse spleen single cell suspension.2.Detection indicators and methods:（1）Flow cytometry was used to detect phenotype receptors of BMDCs.（2）The proliferation of mixed lymphocyte reaction（MLR）lymphocytes was determined by MTT method.（3）Nrf2/p62 silencing BMDCs were established by gene silencing.（4）Real-time quantitative PCR and ELISA were used to detect the content of related cytokines in T lymphocytes and DCs.（5）Western blot was used to detect the content of Nrf2 and other related proteins in DC.Results:1.Inorganic arsenic has an inhibitory effect on DC antigen presentation.After treatment with 1μM AsIII,the mRNA transcription levels of Th1,Th2,Th17 cytokines,Treg cell transcription factors and cytokines decreased,and cytokines Ifn-γ（1:5）and Il-2（1:10）,Il-13（1:10）and Il-4（1:5）,Il-17（1:10）and Il-22（1:10）,transcription factor Foxp3（1:10）,cytokine Il-10（1:10）and Tgf-β（1:10）The difference was statistically significant（P<0.05）.2.After transfecting BMDCs with two Nrf2 siRNAs,compared with As+LPS in Ctr group,the expression of NRF2 and HO-1 protein in As+LPS+A and As+LPS+B groups decreased,the transcription level of Cd40 mRNA in As+LPS+B group was significantly increased,and there was a significant difference（P<0.05）.The levels of TNF-αand IL-1βsecretion and the mRNA transcription level of Il-1βin group A and group B were increased,and there was a significant difference（P<0.05）;the levels of Th1 cytokine IL-12 and Il-12b mRNA transcripts were increased in group A and group B,and the secretion level of Th17 cytokine IL-6 was increased in group B.Significance（P<0.05）.3.After transfection of BMDCs with p62 siRNA and Control siRNA,the expression levels of p62,NRF2,HO-1 and GCLm in As+LPS group were decreased in si p62/SQSTM1 group compared with As+LPS group in si Ctr group.there was a significant difference（P<0.05）;p62,Ho-1,Gclm,Gclc,and Nqo1 mRNA levels were decreased in the si p62/SQSTM1 group,and there was a significant difference（P<0.05）;si p62/SQSTM1 group The transcription levels of Th1 type cytokines Il-12a and Il-12b mRNA increased,respectively,and there was a significant difference（P<0.05）.Conclusion:1.Inorganic arsenic inhibits DC antigen presentation,inhibits T lymphocyte proliferation,and inhibits transcription of related cytokine mRNA in T lymphocytes.2.Nrf2 knockdown induced the expression of BMDCs-associated costimulatory molecules,pro-inflammatory factors,Th1 type cytokines and Th17 type cytokines exposed to inorganic arsenic.3.p62 knockdown inhibited the expression of P62 and NRF2 related proteins and mRNA in BMDCs exposed to inorganic arsenic;induced the transcription level of Th1 cytokine mRNA. |
